Induction heating device and centering guide therefor



July 31, 1956 V/ ///Z T/\()L ATTORNEY July 31, 1956 c. H. BRAUER ETAL INDUCTION HEATING DEVICE AND CENTERING GUIDE THEREFOR 2 Sheets-Sheet 2 Filed Nov. 18, 1953 CH BRAUE .4. 4. 0/0 PM 9 United States Patent 3 INDUCTION HEATING DEVICE AND CENTERDIG GUIDE THEREFOR Clarence H. Brauer and Algirdas A.

111., assignors to International corporation of New Jersey Didziulis, Chicago, Harvester Company, a

This invention relates to an induction heating device for heating and treating the inner walls of cylinder bores. More particularly, this invention relates to a centering guide for induction heating coils.

In the heat treatment of cylinder bores, it is extremely important that the heat treating coil, which is moved progressively throughout the length of the bore, is maintained in consistently spaced relation with respect to the inner wall of the bore. During the heat treatment, the induction coil, including a quench head, is moved progressively within the bore resulting in the formation of a hardened layer of material having a certain desirable grain structure. it is extremely important that this layer is consistent and does not vary throughout the length of the bore. Improper centering of the induction heating coil results in inconsistencies in the hardening. Furthermore, contact by the heating coil with the inner wall of the bore causes an undesirable electrical short which also adversely affects the hardening properties of the cylinder head. It is a prime object of this invention, therefore, to provide an improved centering guide which is attached to the induction device and effectively maintains the device in consistently spaced relation with respect to the inner wall of the cylinder bore.

A still further object is to provide a centering device for centering the induction coil of a progressive heat treating device, the device including members projecting o-utwardly from the device into sliding engagement with the wall of the bore, the members being effective to auto matically maintain the induction coil of the heat treating device in proper centered relation with respect to the bore.

Still another object is to provide a centering device for an induction heating head, the device including elements automatically adjustable in response to variations within the bore to maintain the heating head in correct centered position with respect to the Wall of the bore.

These and further objects will become more readily apparent from a reading of the specification when examined in connection with the accompanying sheets of drawings.

In the drawings:

Figure 1 is a cross-sectional View through one of the bores of a cylinder head, disclosing in side elevation an induction heat treating device having an automatic centering device therefor;

Figure 2 is a sectional view taken along the line 2-2 of Figure 1;

Figure 3 is an enlarged cross-sectional view through a centering device for induction heating heads, the view being taken substantially along the line 33 of Figure 1; and

Figure 4 is a cross-sectional view through a centering device taken along the line 4-4 of Figure 2.

Referring now particularly to Figures 1 and 2, a heat treating device is generally designated by the reference character 10. The heat treating device is shown in connection with a work-piece in the form of a cylinder ice block 11. The cylinder block 11 has one or more conventional cylinder bores 12. Each of these bores 12 has an inner wall 13 surrounded by a chamber or water jacket 14.

The heat treating device 10 includes a quench head 15. The quench head 15 is generally constructed of a phenolic, fiber-like or non-conductor material. The quench head 15 comprises an annular recess 16 in which a conventional hollow induction coil 17 is positioned. The hollow induction coil 17 is suitably connected to the quench head 15 by means of a plate 18 which in turn is connected to a support 19. The quench head 15 includes a chamber 20 provided with a plurality of openings designed to direct a quenching liquid against the wall 13 of the cylinder bore 12. The support 19 has at its upper end a hollow collar 22 which is in turn connected to a conduit 23. A cooling liquid may be directed to the collar 22 from the conduit 23 and to the hollow induction coil 17 in a conventional manner for suitably cooling the induction coil 17 during the heat treating operation.

A hydraulic ram 24 is connected to the support 19, the said ram having a piston rod 24' connected to a support (not shown) in a manner wherein the treating device 10 may be progressively lowered throughout the length of the cylinder bore 12 and retracted with respect thereto. Inlet conduits 25 and 26 are indicated to direct quenching liquid to the quenching chamber 20 in a conventional manner for providing a suitable quench during the progressive heat treating operation of the induction heat treating device It A guide assembly or centering device for the heat treating device 10 is generally indicated by the reference character 27. The guide assembly 27 comprises a lower body portion or member 28 which may, as indicated, be a portion of the phenolic quench head 15. The member 28 is provided with a plurality of radially extending bores 29 which are at their inner open ends in communication with a centrally disposed opening 30. The centrally disposed opening 30 has its axis substantially perpendicular with respect to the axes of the radially extending bores 29, as best shown in Figures 3 and 4.

Each of the bores 29 is provided adjacent its inner end with an enlarged recess 31. Each recess 31 serves to seat the enlarged head 32 of a retaining member 33. Each retaining member 33 is provided with a threaded stub 34 to which the threaded end of a sleeve 35 is connected. Each sleeve 35 is disposed within each bore 29 and each sleeve is provided with an open end bore 36. Each sleeve also includes a cup-shaped recess 37.

A centering plunger 38 is reciprocally positioned with respect to each of the bores 36 and 29. Each plunger includes a guide extension 39 which has one end thereof projecting outwardly and is adapted to contact the wall 13 in relative sliding relation, as best indicated in Figures 3 and 4. A collar 40 is connected to the plunger 38 and a resilient member in the form of a spring 40 is held captive between the collar 40 and the threaded stub 34 for urging the plunger outwardly and the guide extension 39 into contact with the wall 13 of the bore 12.

Each plunger is provided at its other end with an extension or arm 41 projecting into the central opening 30. Each arm 41 includes at its extreme end a hook portion 42. A rotatable wheel or member 43 is rotatably positioned within the opening 30. The rotatable member 43 is provided with a plurality of peripherally extending notches or recesses 44 which receive the hook portions 42 of the arms 41 in mating or connecting relation. The rotatable member is journaled on pins 45, one of said pins 45 being disposed in a recess 46 provided in the member 28. The other pin 45 is journaled in a recess 47 formed in a closure plate 48. The closure plate 48 is removably held in assembly with the member 23 bymeansofaplurality ofscrews 49:

During the operation, the hydraulic ram 24 moves the treating device axially within the bore 12. The induction coil 17 is' suitably connected to a source of audio frequency or'ra'dio frequency current and the wall of the bore is properly heated. After the heating operation, conventional quenching takes place and a layer of the wal113 is properly hardened or heat treated. The. guide assembly. 27"serves to keep the induction coil consistently and. properly spaced with respect to the Wall 13. The guide extensions 39 are in contact with the wall and are maintained'in this contact by means of the springs iii which continually urge the plungers 38 outwardly. The plunger extensions 39 will continually be in contact with the wall 13. despite any irregularities, in the said wall. Thus, the heat treating; device 10' will'be constantly centered. Each guide extension 39 acts asa contact or feeler device whereupon any reciprocating movement of one plunger 38: is immediately imparted to the rotatable member 43' which in turn imparts reciprocation to the other plungers 38. Thus, movement of one of the plungers 38 is imparted to all of the plungers and all plungers move in equal degree, so that the induction coil is. constantly centered in a positive manner despite irregularities in the bore. which is to be hardened. Considering. an extreme-case, for example, one portion of the bore may be. considerably larger than another portion. When the heating device It) is movedto the larger portionof the bore, the plungers will be forced outwardly, willremain-in contact with the wall of the bore; and since the movementof the plungers is all correlated and equal, the treating. device and particularly the hollow induction coil 17 Will be maintained in properly spaced relation, so thatthe, peripheral edge of the coil will be consistently spaced with respect to the adjacent Wall.

Thus, it can be seen that an automatic andself-adjusting guidemeans is provided for an inductioncoil'for heat treating thcinner'walls' of cylindricalworlepieces. it,

oftcourse, can be appreciated that the device may be used for other than-cylinder bores and that'this use is'merely onesapplication to'which the unit may-be applied.

It'can nowbereadily seen that therobjects-of the invention have been fully achieved and that-an improved induc tion device with automatic centering means has beenprovided. Changesand modifications may be made in the designpwithout departing from the spirit of the invention nor. from-the'scope thereof as. definedin the-appended claims,-

What iscclaimed is:

1; Aldevicec for progressively heat: treating the inner.

wall; of acyhndrical:worh-piece comprising. an induction coil having an annular. edge: portion disposed in close proximity; toitheinnerwall, a quench head havingia plurality of. openings-tor. directing" quench liquid'lagainst theinner: wall,.. meansconnected to said. quenclr head for directing: a quenching: fluid thereto, guide: means con nectcdito saidinduction coil, said guide meanscomprising: a: member: having a plurality of circumferentially spaced; transversely extending; bores and substantially centrally. disposed iopeningcommunicatin g witl" said bores and: extending: substantially perpendicular with respect thereto, a gnidesslccve disposed in each' bore, a plunger reciprocally positioned: Within eachvsleeve, each plunger having an extension at one end projecting outwardly from themernbe-r andibeing adapted toengagethe inner wall. oi

the Work-piece in'relative sliding relation, a-hook elc ment'at the other end of each plunger, a resilient Ielerneut confined within each sleeve and engaging each plunger for urgingeach plunger outwardly into'engagementwith the-innerwall, and'za rotatable element disposed in said central 1 opening: for rotation: about an axis substantially perpendicular to thewaxisxof 'thebores; said rotatableele-' ment ;ha.ringza-=plurality of peripherally disposed'notches; the hookelements of saidiplunzgers. having: end 1 portionstion coil, said guide means comprising a member having a plurality of circumferentially spaced bores and. a substantially centrally disposed opening disposed adjacent inner ends of said bores, a guide sleeve disposed in each bore; a plunger reciprocally positioned within'eachsleeve, each plunger having a first extension at one end projecting outwardly from the member and being adapted to engage the inner wall of the work-piece in sliding relation, a second extension at the other end of plunger, saidsec- 0nd. extension projecting. into said central opening, resilient means engaging said plunger within said sleeve for urging said plunger in the direction of said inner. wall, a rotatable element disposed within said central opening rotatable about an axis perpendicular to the axis of said bores, said rotatable element having: a plurality of peripherally disposed notches, and means on said second extensions engaging said notches whereupon reciprocation of one plunger, said rotatable element is rotated and all plungers are moved in concert in equal relation.

3. A device for progressively heat treating the inner wall of a cylindrical work-piece comprising an induction coil having apcripheral edge portion disposed in close proximity to the inner wall, guide means connected to' said induction coil, said guide means comprising a inern her having. a plurality of circumferentially spaced bores anda substantially centrally disposed opening disposed adjacent inner ends of said bores, a guide sleeve disposed in each bore, a plunger reciprocally positioned within each sleeve, each plunger having. afirst extension at one end projecting outwardly from the member and.

being adapted to engage the inner wall of the work-piece in sliding relation, a second-extension'atthe other end of plunger, said second extension projecting into said central opening, resilient means engaging said plunger within said sleeve for urging said plunger in the direction of said inner Wall, a rotatable element disposed Within said central-opening rotatable about an axis perpendicular to the. axisof said bores, saidrotatable element having a:

' tensionat. end projecting. outwardly from the mem-= her and being adapted to engage the innertwallot'the workpiece. in' sliding relation; a" second extension at the other end of each plunger, said second extension projecting into said central opening; resilient meansiengaging said plunger for urginggsaidsplunger in" the. directionofsaid inner'swall, a rotatable element'disposed'within said central opening rotatable about an axis perpendicular to the axis ofxsaid bores; said: rotatable. element having: aiplurality of peripherally disposednotches, andrneans 'on'said secondextension engaging said notches, whereupon=reciprocationaof one Plunger, .saidarotatable element is:ro-'

tated; and all plungers: are' moved i. in concert in? equal relation;

silient means engaging said plunger for g said plun er in the direction of said inner wall, a rotatable element disposed on said member, said rotatable element having a plurality of peripherally disposed notches, and means on said second extension engaging said notches, whereupon reciprocation of one plunger, rotatable element is rotated and all plungers are moved concert in equal relation.

6. A device for progressively heat treating the inner wall of a cylindrical work-piece comprising an induction coil having an edge portion disposed in close proximity to the inner wall, guide means connected to said induction coil, said guide means comprising a member, a plurality of radially extending plungers reciprocally mounted on said member, each plunger having a first extension at one end projecting outwardly from the member and being adapted to engage the inner Wall of the work-piece in sliding relation, a second extension at the other end of plunger, resilient means engaging said plunger for urging said plunger in the direction of said inner Wall, a movable element on said member, and means on each second extension connected to said movable element whereupon reciprocation of one plunger in response to engagement by said one plunger with said wall, said movable element is moved and all plungers are moved in concert in equal relation.

7. A device for progressively heat treating the inner wall of a cylindrical work-piece comprising an induction coil having an edge portion disposed in close proximity to the inner wall, guide means on said induction coil, said guide means including a plurality of radially extending plungers connected to said induction coil for reciprocation with respect thereto, each plunger having a first extension at one end projecting outwardly from the induction coil and being adapted to engage the inner Wall of the workpiece in sliding relation, a second extension at the other end of said plunger, means for urging said plunger in the direction of said inner wall, means connecting said plungers whereupon reciprocation of one plunger in response to engagement by said one plunger with said Wall, all plungers are moved in concert in equal relation.

8. A device for progressively heat treating the inner wall of a cylindrical Work-piece comprising an induction coil having an edge portion disposed in close proximity to the inner wall, guide means connected to said induction coil, said guide means comprising a member, a plurality of plungers reciprocally carried by said member, each plunger having a first end portion projecting outwardly from the member and being adapted to engage the inner wall of the work-piece in sliding relation, a second end portion on each plunger, resilient means engaging said plunger for urging said plunger in the direction of said inner wall, and means connecting said plungers whereupon reciprocation of one plunger in response to engagement by said one plunger with said wall, all plungers are moved in concert in equal relation.

9. A device for progressively heat treating the inner wall of a cylindrical work-piece comprising an induction coil having a peripheral edge portion disposed in close proximity to the inner wall, guide means connected to said induction coil, said guide means comprising a plurality of radially extending plungers reciprocally connected to said coil, each plunger having a first extension at one end projecting outwardly from the coil and being adapted to engage the inner wall of the work-piece in sliding relation, a second extension at the other end of plunger, resilient means engaging said plunger within said sleeve for urging said plunger in the direction of said inner wall, a rotatable element, and means on said second extensions connected to said rotatable element whereupon reciprocation of one plunger in response to engagement by said one plunger with said wall, said rotatable element is rotated and all plungers are moved.

10. A device for progressively heat treating the inner wall of a cylindrical work-piece comprising an induction coil having a peripheral edge portion disposed in close proximity to the inner wall, guide means connected to said induction coil, said guide means comprising a plurality of plungers reciprocally connected to said induction coil, each plunger having one end adapted to engage the inner wall of the workpiece in relative sliding relation, resilient means engaging said plunger for urging said plunger in the direction of said inner wall, and movable means connecting a second end of each plunger whereupon reciprocation of one plunger in response to engagement by said one plunger with said wall, said movable means is moved and all plungers are moved in concert.

References Cited in the file of this patent UNITED STATES PATENTS 2,202,758 Denneen et al May 28, 1940 2,288,038 Somes June 30, 1942 2,358,834 Somes Sept. 26, 1944 2,495.474 Phillips Jan. 24, 1950 

